A bearing is incorporated in motors to be mounted to electric devices such as an exhaust fan, and the bearing supports a rotary shaft in a freely rotatable manner. For use of this type, there has been generally used what is called a rolling bearing including: an outer race; an inner race; a plurality of rolling elements arranged between the inner and outer races; and a retainer for retaining the rolling elements (for example, Patent Literature 1).
Meanwhile, as a fluid dynamic bearing device, there has been provided a fluid dynamic bearing device including: an outer member formed of a cylindrical bearing ring and bearing plates fitted to both ends of the bearing ring; and an inner bearing plate member arranged on an inside of the outer member (Patent Literature 2).